1. The problem statement, all variables and given/known data I'm trying to solve the following problem : In △ABC, coordinates of B are (−3,3). Equation of the perpendicular bisector of side AB is 2x+y−7=0. Equation of the perpendicular bisector of side BC is 3x−y−3=0. Mid point of side AC is E(11/2,7/2). Find AC2. 2. Relevant equations - 3. The attempt at a solution By solving 3x−y−3=0 and 2x+y−7=0 I find that the intersection of perpendicular bisectors is at (2,3) . Then using the two points (2,3) and (11/2,7/2), I get the equation of perpendicular bisector of AC as y=x/7+19/7. So the slope of AC is -7 and then using point slope form , y−7/2=−7(x−11/2) Thus the equation of line AC is y=42−7x . Similarly equation of line BC is y=2−x/3 . So AC and BC intersect at (6,0). By using the fact that E is the midpoint of AC, I find Co-ordinates of A as (5,7). So the distance between A and C is 5√2, and AC2=50. But this answer is wrong and the correct answer is 74 ( I checked the answer sheet) . What have I done wrong ?